Thermal inkjet printers utilize one or more printheads to deposit ink on paper and other print media. A printhead is a micro-electromechanical part that contains an array of miniature thermal resistors that are energized to eject small droplets of ink out of an associated array of orifices. Air and other gases may form in the ink moving through the printhead as the ink is heated and cooled. Gas bubbles allowed to accumulate near the printhead can eventually displace all of the ink at the printhead, causing the printhead to lose its prime and rendering the printhead useless. It is desirable, therefore, to move air and other gas bubbles away from the printhead.